I don’t use Bambu filament and always calibrate my filaments.
From there I know that the Bambu profiles are only really optimised enough for 0.2mm.
Anything below that and the filament calibration becomes rather crucial.
Just to the basic math based on the nozzle diameter and layer height in use.
You will how quickly the extrusion volume goes down with the layer height and how then any flaw increases the low the layers are.
My standard matte PLA rolls produce near perfect prints all the time and that (if the model allows for it) at speeds of up to 450mm/s.
But just going one profile lower to 0.12mm layers and high quality and all hell breaks loose unless I select a filament profile with a matching calibration.
Worse when trying 0.8mm layers with the filament profile unchanged.
I am still not 100% sure whether this calibration flaw is within the defaults or just a matter of how the default calibration only works for 0.2mm layers.
But I do know that some filaments are pain to check with the Bambu patches, like clear or matte filaments.
Where I would get lets say a 1.02 flow ratio after checking the patches from all possible angles with a good magnifying glass, doing it manually and old school often provides a difference either direction of up to 0.2 - MORE than enough to throw things off at low layer heights.
For some of the harder to check filaments the difference can be up to 0.3 in my tests.
I think Orca does better calibration job than Studio but I also think Bambu should provide a way to calibrate filaments based on the lowest layer height and highest quality settings.
Preferably though just a calibration that does not take over and hour and then still is inconclusive…
K-factor and flow ration should be calibrated together and also work for all layer heights and quality settings.
Until this works as advertised my best suggestion is to properly calibrate the filaments for lower layer heights - even if it means adding a filament profile for just that.